1. Field of the Invention
One embodiment of the present invention relates to an electrode, a power storage device, an electronic device, and a method for manufacturing any of them.
Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an imaging device, a method for driving any of them, and a method for manufacturing any of them.
In this specification, the power storage device is a collective term describing units and devices having a power storage function. For example, a storage battery such as a lithium-ion secondary battery (also referred to as secondary battery), a lithium-ion capacitor, and an electric double layer capacitor are included in the category of the power storage device.
2. Description of the Related Art
In recent years, a variety of power storage devices, for example, lithium-ion secondary batteries, lithium-ion capacitors, and air cells have been actively developed. In particular, demand for lithium-ion secondary batteries with high output and high energy density has rapidly grown with the development of the semiconductor industry, for portable information terminals such as mobile phones, smartphones, and laptop computers, portable music players, and digital cameras; medical equipment; next-generation clean energy vehicles such as hybrid electric vehicles (HEV), electric vehicles (EV), and plug-in hybrid electric vehicles (PHEV); and the like. The lithium-ion secondary batteries are essential as rechargeable energy supply sources for today's information society.
As described above, lithium-ion secondary batteries have been used for a variety of purposes in various fields. Properties necessary for such lithium-ion secondary batteries are high energy density, excellent cycle characteristics, safety in a variety of operation environments, and the like.
In addition, the lithium-ion secondary battery includes at least a positive electrode, a negative electrode, and an electrolytic solution (Patent Document 1).